Comparison of postoperative cognitive decline in patients undergoing conventional vs miniaturized cardiopulmonary bypass: A randomized, controlled trial

Associations between postoperative cognitive dysfunction, serum interleukin-6 and postoperative delirium among patients after coronary artery bypass grafting: A mediation analysis

BACKGROUND

POCD is a common complication among patients who underwent coronary artery bypass graft (CABG), it is linked to loss of independence and reduced quality of life.

AIMS AND OBJECTIVES

To examine the association between postoperative cognitive dysfunction (POCD), postoperative delirium (POD) and interleukin-6 (IL-6).

DESIGN

A prospective cohort study.

METHODS

Patients who underwent elective isolated CABG were enrolled. POCD was assessed by a set of cognitive function tools. Delirium was assessed using the CAM-ICU. The logistic regression analyses were used to identify the predictive value of POD or IL-6 on POCD. The path analysis was used to analyse the relationship among POD, IL-6 and POCD.

RESULTS

A total of 212 patients were enrolled, with 25.0% of patients developing POD and 32.5% developing POCD. The multiple logistic regression analysis revealed that patients with POD had a four-fold increased hazard of POCD (OR = 3.655), and patients with IL-6 ≥ 830.50 pg/mL at the 6th hours after surgery had a 5-fold increased risk of experiencing POCD (OR = 5.042). However, the mediation effect of POD between IL-6 and POCD was not statistically significant (β = 0.059, p = .392).

CONCLUSIONS

POD and IL-6 at the 6th hour after surgery (≥830.50 pg/mL) are two potent predictors for POCD, while POD did not play a mediation effect between IL-6 and POCD.

RELEVANCE TO CLINICAL PRACTICE

Early identification of risk factors (e.g., delirium assessment and testing for serum IL-6 levels) by clinical nurses for POCD may contribute to the clinical practice for the targeted prevention nursing strategies.

The link between the early surgery-induced inflammatory response and postoperative cognitive dysfunction in older patients

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a common complication in older patients with cancer and is associated with decreased quality of life and increased disability and mortality rates. Systemic inflammation resulting in neuroinflammation is considered important in the pathogenesis of POCD. The aim of this study was to explore the association between the early surgery-induced inflammatory response and POCD within 3 months after surgery in older cancer patients.

METHODS

Patients ≥65 years in need of surgery for a solid tumor were included in a prospective cohort study. Plasma levels of C-reactive protein (CRP), interleukin-1 beta (IL-1β), IL-6, IL-10, and Neutrophil gelatinase-associated lipocalin (NGAL) were measured perioperatively. Cognitive performance was assessed preoperatively and 3 months after surgery. POCD was defined as a decline in cognitive test scores of ≥25% on ≥2 of five tests within the different cognitive domains of memory, executive functioning, and information processing speed. Logistic regression analysis was performed.

RESULTS

POCD was observed in 44 (17.7%) of 248 included patients. Age >75, preoperative Mini-Mental State Examination (MMSE) score ≤26 and major surgery were independent significant predictors for POCD. In multivariate logistic regression analysis, no significant associations were shown between the early surgery-induced inflammatory response and either POCD or decline within the different cognitive domains.

CONCLUSIONS

This study shows that one out of six older patients with cancer developed POCD within 3 months after surgery. The early surgery-induced inflammatory response was neither associated with POCD, nor with decline in the separate cognitive domains. Further research is necessary for better understanding of the complex etiology of POCD.

Postoperative cognitive dysfunction: Review of pathophysiology, diagnostics and preventive strategies

Postoperative cognitive impairment is a common disorder after major surgery. Advances in medicine and treatment have resulted in an increasingly ageing population undergoing major surgical procedures. Since age is the most important risk factor for postoperative cognitive decline, it is not surprising that impairment of cognitive functions after surgery was recorded in almost a third of elderly patients. Postoperative cognitive dysfunction is part of the spectrum of postoperative cognitive impairment and researchers often confuse it with postoperative delirium and delayed neurocognitive recovery. This is the cause of great differences in the results of research that is focused on the incidence and possible prevention of postoperative cognitive dysfunction. In this review, we focused on current recommendations for a uniform nomenclature of postoperative cognitive impairment and diagnosis of postoperative cognitive dysfunction, the presumed pathophysiology of postoperative cognitive dysfunction and recommendations for its treatment and possible prevention strategies.

A Comparison of the Clinical Outcomes of Minimum and Maximum Hematocrit Levels During Cardiopulmonary Bypass (CPB) in Low-risk Patients Undergoing Coronary Artery Bypass Graft Surgery (CABG): A Cross-sectional Study

Background

This study investigated the clinical outcomes at the minimum and maximum levels of hematocrit (HCT) during cardiopulmonary bypass (CPB) in low-risk patients undergoing coronary artery bypass graft (CABG) surgery.

Materials and Methods

In this cross-sectional study, 85 patients who underwent CABG with an ejection fraction of greater than 35% were selected. Based on the HCT range during CPB, patients were divided into two groups: minimum HCT: HCT = 16-18% and maximum HCT: HCT = 25-27%. Then the operation outcomes, amount of drainage, and transfusion were recorded and compared between these groups.

Results

In the middle tube 8 h after surgery and left tube 24 h after surgery, the amount of drainage in the minimum HCT group with mean of 71.00 ± 130.9 and 60.65 ± 71.23, respectively, was significantly lower than the maximum HCT group with mean of 101.5 ± 246.50 and 123.76 ± 93.17, respectively (P value < 0.05). The incidence of cognitive disorders in the maximum HCT group was significantly higher than in the minimum HCT group (11.1% vs. 0%, P value = 0.041). Also, the mean transfusion of packed red blood cell (PRBC) and fresh frozen plasm (FFP) during CPB in the maximum HCT group, with mean of 346.7 ± 86.22 and 396.1 ± 21.05, respectively, were significantly higher than the minimum HCT group with mean of 178.8 ± 80.91 and 136.8 ± 46.77, respectively (P value < 0.05). After CPB, there was no significant difference in transfusion products (P value > 0.05).

Conclusion

According to the results of this study, patients undergoing CABG surgery with maximum HCT level versus minimum HCT level during CPB, need more packed cells and fresh frozen plasma products transfusion, which will be associated with the complication of cognitive impairment.

Effects of interventions targeting the systemic inflammatory response to cardiac surgery on clinical outcomes in adults

BACKGROUND

Organ injury is a common and severe complication of cardiac surgery that contributes to the majority of deaths. There are no effective treatment or prevention strategies. It has been suggested that innate immune system activation may have a causal role in organ injury. A wide range of organ protection interventions targeting the innate immune response have been evaluated in randomised controlled trials (RCTs) in adult cardiac surgery patients, with inconsistent results in terms of effectiveness.

OBJECTIVES

The aim of the review was to summarise the results of RCTs of organ protection interventions targeting the innate immune response in adult cardiac surgery. The review considered whether the interventions had a treatment effect on inflammation, important clinical outcomes, or both.

SEARCH METHODS

CENTRAL, MEDLINE, Embase, conference proceedings and two trial registers were searched on October 2022 together with reference checking to identify additional studies.

SELECTION CRITERIA

RCTs comparing organ protection interventions targeting the innate immune response versus placebo or no treatment in adult patients undergoing cardiac surgery where the treatment effect on innate immune activation and on clinical outcomes of interest were reported.

DATA COLLECTION AND ANALYSIS

Searches, study selection, quality assessment, and data extractions were performed independently by pairs of authors. The primary inflammation outcomes were peak IL-6 and IL-8 concentrations in blood post-surgery. The primary clinical outcome was in-hospital or 30-day mortality. Treatment effects were expressed as risk ratios (RR) and standardised mean difference (SMD) with 95% confidence intervals (CI). Meta-analyses were performed using random effects models, and heterogeneity was assessed using I2.

MAIN RESULTS

A total of 40,255 participants from 328 RCTs were included in the synthesis. The effects of treatments on IL-6 (SMD -0.77, 95% CI -0.97 to -0.58, I2 = 92%) and IL-8 (SMD -0.92, 95% CI -1.20 to -0.65, I2 = 91%) were unclear due to heterogeneity. Heterogeneity for inflammation outcomes persisted across multiple sensitivity and moderator analyses. The pooled treatment effect for in-hospital or 30-day mortality was RR 0.78, 95% CI 0.68 to 0.91, I2 = 0%, suggesting a significant clinical benefit. There was little or no treatment effect on mortality when analyses were restricted to studies at low risk of bias. Post hoc analyses failed to demonstrate consistent treatment effects on inflammation and clinical outcomes. Levels of certainty for pooled treatment effects on the primary outcomes were very low.

AUTHORS' CONCLUSIONS

A systematic review of RCTs of organ protection interventions targeting innate immune system activation did not resolve uncertainty as to the effectiveness of these treatments, or the role of innate immunity in organ injury following cardiac surgery.

2021 MiECTiS focused update on the 2016 position paper for the use of minimal invasive extracorporeal circulation in cardiac surgery

The landmark 2016 Minimal Invasive Extracorporeal Technologies International Society (MiECTiS) position paper promoted the creation of a common language between cardiac surgeons, anesthesiologists and perfusionists which led to the development of a stable framework that paved the way for the advancement of minimal invasive perfusion and related technologies. The current expert consensus document offers an update in areas for which new evidence has emerged. In the light of published literature, modular minimal invasive extracorporeal circulation (MiECC) has been established as a safe and effective perfusion technique that increases biocompatibility and ultimately ensures perfusion safety in all adult cardiac surgical procedures, including re-operations, aortic arch and emergency surgery. Moreover, it was recognized that incorporation of MiECC strategies advances minimal invasive cardiac surgery (MICS) by combining reduced surgical trauma with minimal physiologic derangements. Minimal Invasive Extracorporeal Technologies International Society considers MiECC as a physiologically-based multidisciplinary strategy for performing cardiac surgery that is associated with significant evidence-based clinical benefit that has accrued over the years. Widespread adoption of this technology is thus strongly advocated to obtain additional healthcare benefit while advancing patient care.

Effect of different coronary artery revascularization procedures on cognition: A systematic review

Coronary revascularization interventions have been associated with post-intervention cognitive decline. Hence, this systematic review aims to compare the long-term effects of different coronary revascularization interventions on cognition. The Cochrane Library and MEDLINE databases were searched for articles published between January 2009 and January 2023. Articles on clinical trials and cohort studies that compared at least two different interventions with a minimum three months follow up were included to evaluate the consequences of different intervention techniques on cognition. Each selected study was evaluated using a revised tool to assess the risk of bias in randomized trials (RoB 2), and Risk of Bias In Non-Randomized Studies - of Interventions(ROBINS-1) was used for evaluating non-randomized studies. Five eligible studies, with four different comparisons, were included. Out of these studies, three RCTs and two cohort studies were included A participants gone through different procedures; on-pump and off-pump coronary artery bypass grafting (CABG), Percutaneous coronary intervention (PCI conventional cardiopulmonary bypass (CCPB), the miniaturized cardiopulmonary bypass (MCPB) and endoscopic coronary artery bypass grafting (Endo-CABG). These comparisons showed that different interventions have different effects on cognition; however, there is no solid evidence of correlations between them. Thus, the results of this review suggest that there should be greater focus on comparing interventions and that a reasonable follow-up duration should be set to avoid the influence of confounders. There is also a need to determine the effect of long-term cognitive decline while reducing interference by other variables.

Postoperative Delirium and Dementia in Patients Undergoing Cardiac Surgery: A Review of Randomized Controlled Trials

Delirium and dementia are considered to be the most significant postoperative neurocognitive complications in patients undergoing cardiac surgery, particularly those aged 60 years and older, which reduces the post-surgery quality of life, prolongs hospitalization, increases costs, and elevated the rates of mortality. Nevertheless, the etiology, risk factors, and predictive biomarkers, have not been well elucidated particularly, in patients with unmanifested underline cognitive impairments. The present study aimed to review the findings on the etiology, factors increasing the risk of incidence, and predictive biomarkers of postoperative delirium and dementia after cardiac surgery, and to describe the suggested pharmacological and non-pharmacological interventions.

Post-Operative Cognitive Impairment: A Cognitive Epidemiology Perspective

Cognitive epidemiology investigates cognitive predictors of health and disease outcomes. Post-operative cognitive impairment is a common complication of surgery but has been neglected as a health outcome in cognitive epidemiology research. This is despite the fact that knowledge of cognitive predictors of post-operative cognitive impairment can be utilized for risk stratification, informed decision-making (in elective surgery), and personalized care of patients during the postoperative period. In this narrative review, the current literature on cognitive predictors of post-operative cognitive impairment and gaps therein are summarized.

Conventional versus miniaturized cardiopulmonary bypass: A systematic review and meta-analysis

Objective

A meta-analysis of randomized controlled trials was performed to compare the effects of miniaturized extracorporeal circulation (MECC) and conventional extracorporeal circulation (CECC) on morbidity and mortality rates after cardiac surgery.

Methods

A comprehensive literature search was conducted using Ovid, PubMed, Medline, EMBASE, and the Cochrane databases. Randomized controlled trials from the year 2000 with n > 40 patients were considered. Key search terms included variations of “mini,” “cardiopulmonary,” “bypass,” “extracorporeal,” “perfusion,” and “circuit.” Studies were assessed for bias using the Cochrane Risk of Bias tool. The primary outcomes were postoperative mortality and stroke. Secondary outcomes included arrhythmia, myocardial infarction, renal failure, blood loss, and a composite outcome comprised of mortality, stroke, myocardial infarction and renal failure. Duration of intensive care unit, and hospital stay was also recorded.

Results

The 42 studies eligible for this study included a total of 2154 patients who underwent CECC and 2196 patients who underwent MECC. There were no significant differences in any preoperative or demographic characteristics. Compared with CECC, MECC did not reduce the incidence of mortality, stroke, myocardial infarction, and renal failure but did significantly decrease the composite of these outcomes (odds ratio, 0.64; 95% confidence interval [CI], 0.50-0.81; P = .0002). MECC was also associated with reductions in arrhythmia (odds ratio, 0.67; 95% CI, 0.54-0.83; P = .0003), blood loss (mean difference [MD], –96.37 mL; 95% CI, –152.70 to –40.05 mL; P = .0008), hospital stay (MD, –0.70 days; 95% CI, –1.21 to –0.20 days; P = .006), and intensive care unit stay (MD, –2.27 hours; 95% CI, –3.03 to –1.50 hours; P < .001).

Conclusions

MECC demonstrates clinical benefits compared with CECC. Further studies are required to perform a cost–utility analysis and to assess the long-term outcomes of MECC. These should use standardized definitions of endpoints such as mortality and renal failure to reduce inconsistency in outcome reporting.